Input Device

1. An input device, comprising: a holder; a first wheel, disposed on the holder, wherein the first wheel comprises a side surface, a circle center, and a segment adjusting structure, wherein the segment adjusting structure is disposed on the side surface and comprises a first sub-segment structure and a second sub-segment structure, wherein the first sub-segment structure and the second sub-segment structure are respectively disposed around the circle center, and the first sub-segment structure is located between the circle center and the second sub-segment structure; a slider, disposed on the holder, and being movable relative to the holder to move toward or away from the circle center; and a first pressure part, comprising two first ends, wherein one of the first ends is connected to the slider, when the slider moves toward the circle center, the other of the first ends contacts the first sub-segment structure, when the slider moves away from the circle center, the other of the first ends contacts the second sub-segment structure, wherein a portion of the first pressure part between the first ends is extended in a direction substantially parallel to an extending direction of a portion of the first sub-segment structure or the second sub-segment structure contacted by the other of the first ends.

2. The input device according to claim 1 , wherein a quantity of segments of the first sub-segment structure is different from a quantity of segments of the second sub-segment structure.

3. The input device according to claim 2 , wherein the first sub-segment structure and the second sub-segment structure comprise a plurality of segments protruding from the side surface in an axial direction of the first wheel, and the segments are in a conical shape.

4. The input device according to claim 1 , wherein the first pressure part is a spring plate or a torsion spring.

5. The input device according to claim 1 , wherein the first sub-segment structure and the second sub-segment structure comprise a plurality of segments protruding from the side surface in an axial direction of the first wheel, each of the segments has a top surface away from the side surface and a bottom surface contacting the side surface, the top surface is smaller than the bottom surface.

6. The input device according to claim 5 , wherein each of the segments further has an inclined surface between the top surface and the bottom surface, a gradient of the inclined surface of each of the segments of the first sub-segment structure is smaller than a gradient of the inclined surface of each of the segments of the second sub-segment structure.

7. The input device according to claim 1 , wherein the first end contacting the first sub-segment structure or the second sub-segment structure is formed as a curved rod.

8. The input device according to claim 1 , wherein a movement direction of the slider is substantially perpendicular to an axial direction of the first wheel.

9. The input device according to claim 1 , wherein the first sub-segment structure and the second sub-segment structure are ring gears spaced at a distance in a radial direction of the first wheel.

10. An input device, comprising: a holder; a first wheel, disposed on the holder, wherein the first wheel comprises a outer surface, a side surface, a center, and a segment adjusting structure, wherein the side surface is connected to and surrounded by the outer surface, the segment adjusting structure is disposed on the side surface and comprises a first sub-segment structure and a second sub-segment structure respectively disposed around the center, and the first sub-segment structure is located between the center and the second sub-segment structure; a slider, disposed on the holder at a position corresponding to the outer surface of the first wheel; and a first pressure part, comprising a first side coupled to the slider and a second side opposite to the first side, when the slider moves toward the center, the second side contacts the first sub-segment structure, when the slider moves away from the center, the second side contacts the second sub-segment structure.

11. The input device according to claim 10 , wherein the slider faces towards the outer surface of the first wheel, and is movable in a direction substantially perpendicular to an axial direction of the first wheel.

12. The input device according to claim 10 , wherein a quantity of segments of the first sub-segment structure is different from a quantity of segments of the second sub-segment structure.

13. The input device according to claim 10 , wherein the first pressure part connected to the slider is extended from the outer surface towards the first sub-segment structure of the first wheel, and the second side of the first pressure part comprises a bent metal bar contacting the first sub-segment structure or the second sub-segment structure.

14. The input device according to claim 10 , wherein a projection of the slider projected onto a plane where the side surface exists is out of the side surface.